This invention relates to an opening roller arrangement for open-end spinning machines and a method of manufacturing same. Such opening roller arrangements include a cylindrical part with toothed rings and intermediate rings alternately slidably disposed thereon. The toothed rings and intermediate rings are clamped between axial stops, the radial surface of which facing one another being wavy to form a wavy configuration of the rings.
In practice, two different types of opening rollers are currently being used in open-end spinning machines which are chosen as a function of the fiber material to be spun. In the case of one type, the circumferential surface of the opening roller is covered with a plurality of needles. In the other type which is used much more frequently, a saw tooth wire is wound spirally around the circumference of the opening roller, the start and end of said winding being fixed at the opening roller. This saw tooth wire is either wound into a corresponding spiral groove of the roller or on the smooth surface thereof. These rollers that are wound with saw tooth wire present difficulties in the practical application because, on the one hand, they are expensive to manufacture and because, on the other hand, they are subject to poor wear characteristics. In order to permit the winding of the saw tooth wire on the roller, the saw tooth wire cannot be hardened or can only be hardened slightly making the hardening process more difficult in the area of the base of the teeth. The reduced hardness in the area of the base of the teeth also results in the fact that increased wear occurs at these points.
In order to avoid the difficulties of the saw-tooth wire wound opening rollers, it has also become known (French-PS No. 15 04 873) to slide toothed rings and intermediate rings alternately on a cylindrical part. In circumferential direction, these toothed rings and intermediate rings each have a wavy shape and are clamped between axial stops, the radial surfaces of which facing one another being provided with corresponding waviness. Thes stops are themselves secured in axial direction by means of flanges, where one of the flanges is made in one piece with the cylindrical part, while the other flange is screwed onto the cylindrical part. Opening rollers of this type have not been used in practice, apparently because the manufacturing costs are still very high and because there are further disadvantages as compared to the opening rollers wound with saw tooth wire. Extensive expenditures are required to construct the toothed disks as well as the intermediate rings and the surfaces of the axial stops facing one another with a wavy shape that is as identical as possible. Despite high manufacturing costs, it can nevertheless also not be avoided in series production that imprecisions occur between the wavy shape of the individual parts and also their thickness, so that after the assembly of the individual parts, open gaps remain between the toothed rings and the intermediate rings and also the stops. In this case, there is the considerable danger that fibers catch in these gaps which will rapidly lead to an obstruction of the opening roller in the housing surrounding it so that the configuration and possibly also the normally uninterrupted drive or the bearing means of the opening roller may be destroyed.
The invention is based on the objectives of providing a construction of an opening roller of the initially mentioned type which, without extensive manufacturing expenditures, can be built in such a way that gaps between the intermediate rings and the toothed rings are avoided.
This objective is achieved according to the invention by the fact that when clamping the toothed rings and the intermediate rings between the axial stops, the intermediate rings are made of a softer material than the toothed rings and are plastically deformed.
By means of the plastic deformation of the intermediate rings at the time of the clamping, these intermediate rings adapt themselves so smoothly to the toothed rings that possible previously existing gaps are completely closed. The thickness of the toothed rings and also that of the intermediate rings may differ with respect to one another or even over the circumference of a toothed ring or an intermediate ring without resulting in the formation of gaps in the finished opening roller. Also, the axial stops and their wavy surfaces do not have to be manufactured with extensively narrow tolerances without the danger of a formation of gaps. Based on the low requirements with respect to tolerances, the individual parts may simply and cost-effectively be manufactured in series production without high manufacturing expenditures.
In an advantageous arrangement of the invention, it is provided that the axial stops are fixed in their position with respect to one another after the deformation of the intermediate rings. This prevents that elastic forces that may still be effective lead to a loosening and thus to a formation of gaps.
In an advantageous arrangement of certain preferred embodiments of the invention, it is provided that the toothed rings are made of a spring steel and the intermediate rings are made of a deep-drawn metal alloy. This pairing of materials permits the desired plastic deformation of the intermediate rings during the clamping.
In an especially advantageous arrangement of the invention, it is provided that the toothed rings are hardened over their whole radial rings before their assembly. The hardening process for toothed rings of this type is much less expensive than the hardening process for saw tooth wire that differs over the radial rings, so that the hardening is considerably simplified and is also more suitable for series production. The base of the teeth which are susceptible to wear is also hardened in this arrangement of the invention.
In a further arrangement of the invention, it is also provided that the toothed rings have teeth, the bases of which are arranged on a diameter that is slightly larger than the outside diameter of the intermediate rings. By means of this arrangement, it is achieved that the intermediate rings do not extend into the area of the teeth of the toothed rings during their plastic deformation.
In a further arrangement of the invention, it is provided that the toothed rings are manufactured in a flat, plane shape and are elastically deformed during the clamping. This arrangement results in a further simplification of the manufacturing process because the toothed rings do not have to be preformed into a wavy shape so that one work step can be saved.
In an advantageous arrangement of the invention, it is provided that the toothed rings have the same thickness from the top of the teeth to the inside diameter. This reduces the material requirement for the toothed rings, while in addition the hardening process is simplified because of the same material thickness. It is especially favorable when the toothed rings have a thickness of about 0.2 mm.
In an especially advantageous arrangement of the invention, it is provided that the toothed rings are punched out of flat bars or strips. This results in a very cost-effective and still very precise manufacturing of the toothed rings which meets especially the requirements of a series production.
In an especially advantageous embodiment of the invention, it is provided that the intermediate rings are manufactured from an aluminum alloy. This results, on the one hand, in the desired deformability for mating of the intermediate rings and of the toothed rings, while, on the other hand, the intermediate rings are not threatened by corrosion.
Embodiments of the invention are contemplated wherein the intermediate rings are manufactured in a form that is preshaped in the form of waves. Since the intermediate rings are plastically deformed, this preshaping does not have to take place with excessive precision without disadvantages. However, in an especially advantageous development, it is provided that the intermediate rings are made in a flat shape. The intermediate rings which are relatively easily deformable, in comparison to the toothed rings, are then shaped into the wavy shape at the time of the clamping so that a preceding shaping becomes superfluous. This reduces the manufacturing expenses further. In practice, it was found that particularly good results are obtained when the intermediate rings are manufactured in a thickness that amounts to about 6 to 10 times the thickness of the toothed rings.
In a further arrangement of the invention, it is provided that the intermediate rings are manufactured in such a way that they have a larger thickness in the area of their outside diameter than in the area of their inside diameter before the clamping. This results in a plastic deformation mainly in the area of their outside diameter during the clamping which is decisive with respect to the fact that gaps existing before the clamping between the toothed rings and the intermediate rings are completely closed. In this case, it is especially advantageous when the intermediate rings have a trapezoid cross section which increases from the inside diameter to the outside diameter.
In a further arrangement of the invention, it is provided that the intermediate rings are punched out of a strip material. This results in an especially simple manufacturing of the intermediate rings with high precision that meets the requirements of series production. In this case, a deforming of the intermediate rings may take place simultaneously with the punching process, providing said intermediate rings with increased strength or thickness in the range of their outside diameter.
In a further development of certain embodiments of the invention, it is provided that the axial stops are made of the same material as the intermediate rings and have a thickness which also in the area of its wave hollows or valleys, amounts to at least twice the thickness of the intermediate rings. By means of this development, it is made possible to connect toothed rings directly to the axial stops, in which case, gaps that may possibly exist before the clamping are closed by the plastic deformation of the axial stops in their contact area at the toothed rings. Because of the increased wall thickness, it is ensured that a reshaping does not take place after the plastic deformation of the intermediate rings and also of the inside edges of the stops. It is advantageous in this case when the axial stops in an area having the wavy radial surface have an outside diameter that corresponds to the outside diameter of the intermediate rings, and when a collar connects with this area that has a diameter reaching at least to the tips of the teeth of the toothed rings. On the one hand, a protection of the teeth tips is provided, especially during the conveying of the opening rollers, while, on the other hand, the stops are strengthened further so that forces existing after the clamping do not threaten a loosening by the deforming of the stops.
In an advantageous arrangement of the invention, it is provided that one of the axial stops is made in one piece with the preferably cylindrical part, while the other stop is slid onto the cylindrical part after the toothed rings and the intermediate rings, with a narrow fit. This simplifies the manufacture of the stops and also the overall assembly. In order to avoid that the stop slid onto the part is loosened, it is provided in an expedient development that, after the sliding of the stop onto the cylindrical part and the plastic deformation of the intermediate rings, a plastic deformation takes place of the front sides of the stop and of the cylindrical part, in the area of the fit. By means of this plastic deformation--a so-called calking--an effective securing of the position takes place.
In another advantageous development of the invention, it is provided that the preferably cylindrical basic part is manufactured as a shell, is provided with the toothed rings, the intermediate rings and the second axial stop and is then detachably mounted on a roller-shaped basic part. Thus, an opening roller is created where the preferably cylindrical part which is provided with the set, i.e., the toothed rings, is constructed as an exchangeable component.
According to the invention, an opening roller is provided where on a preferably cylindrical part, alternately toothed rings made of spring steel and intermediate rings made of a more easily deformable material are arranged which each have a waviness in circumferential direction and which are clamped between axial stops, whose radial surfaces facing one another have a corresponding waviness. The intermediate rings under plastic deformation are smoothly adapted to the toothed rings. Based on this adaptation through plastic deformation, gaps that may previously have existed because of manufacturing tolerances between the toothed rings and the intermediate rings and also the axial stops, are closed. In this case, it is sufficient when only the axial stops have a waviness because the toothed rings and intermediate rings will then, during the clamping, elastically and plastically deform correspondingly and adapt to this waviness.
It is especially advantageous when the waviness has an overall amplitude in axial direction of about the thickness of the intermediate rings. The result is that a sliver is definitely combed out over its whole range without the height or depth of the waves having to be excessively large.
In an expedient embodiment of the invention, it is provided that four waves are provided that are evenly distributed over the circumference of the roller for each toothed ring. It was found in practice that this number of waves is sufficient, at which during a rotation of the opening roller, the fed sliver is combed out with four wave sections.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings which show, for purposes of illustration only, embodiments in accordance with the present invention.